On Debris Flow Disasters on Steep Slopes Facing the Kagoshima Bay, Caused by the Torrential Rain of August 6, 1993, Kyushu

Abstract

This paper aims to report a result of the research on debris flow disasters which occurred at Ryugamizu and 11 other spots along 3-kilometer distance between Ryugamizu and Hiramatsu.
On August 6, 1993, Kagoshima area was struck by a record-high torrential rain, which caused a number of slope failures and debris flows on steep slopes facing the Kagoshima Bay. The debris flows destroyed several houses and washed away a part of the Japan Railroad track and flew over with a great volume of massive sediment on the JR track and the road.
It was found that first slope failures occurred at the upper steep slopes, followed by debris flow, which reached down the railroad and the road. The debris flow from the Ryugamizu-kita slope reached down onto the sea.